Total marks 22

Data set A summarizes F2 numbers from an F1 cross arising from two, true-breeding Drosophila

strains (P generation), which differ with respect to two mutant traits. The genes can be

autosomal or X-linked and the mutant alleles can be dominant or recessive or incompletely or

co-dominant. Do the following:

Attach your completed Section 1, with corrections (if any), so we can see your genetic

hypothesis etc.

b) Analyze whether the data fits your genetic hypothesis by performing a chi-square test.

To begin, state your null hypothesis. 1 mark

c) Perform a chi-square analysis. Make sure to analyze your traits to be consistent with

Section 1 (using the traits separated). Clearly present your results in a table form as you

were shown in exercises for Tutorial 5. (Hint: should the traits be tested in males and

females?) 10 marks

d) State the correct # of degrees of freedom 2 marks

e) Calculate the chi-square value. 2 marks

f) Show the approximate p value. 2 marks

g) Make a statement of how the p value relates to whether you decided to reject or not

reject, your null hypothesis. 2 marks

h) Finally, make a concluding statement about your original genetic hypothesis(es) based

on chi-square analysis. 2 marks

Wt females 545 a + c 33 Wt males 272 + b c 3470 1094 + + + 334 552 + + c 335 544 a + + 3480 277 + b + 32 Grey stripe females Grey stripe males White stripe female White stripe male Hairy leg, grey stripe males Hairy leg male Hairy leg, white stripe males *black body stripe is wildtype 553 a b c 330 269 a b + 332 278 Wt females 545 a + c 33 Wt males 272 + b c 3470 1094 + + + 334 552 + + c 335 544 a + + 3480 277 + b + 32 Grey stripe females Grey stripe males White stripe female White stripe male Hairy leg, grey stripe males Hairy leg male Hairy leg, white stripe males *black body stripe is wildtype 553 a b c 330 269 a b + 332 278